Lubricant.



feeding boilers.

UNITED STATES PATENT OFFICE.

LEONARD CHAPMAN, OF LONDON, ENGLAND, ASSIGNOR OF ONE-HALF TO WILLIAM HUMPHREY KNOWLES, OF LONDON, ENGLAND.

LUBRICANT;

Specification of Letters Patent.

Patented Dec. 1, 1908.

Application filed August 2,0, 1906. Serial No. 331,397.

parts of steam engines, is coupled with seri ous disadvantages, particularly in engines, the condensation water of which is used for I have discovered that glycerin offers in its physical and chemical'properties, pecul iarities which render its use uncommon y advantageous for lubricating the internal parts of steam engines, particularly of steam engines the condensed water of which is used for feeding the boilers. 1

Glycerin is entirely indifferent as against metallic surfaces; it has a 'high boiling point; does not gum; is soluble in water,

and dissolves certain alkalies and alkalineearths, as well as salts of the same. It hinders the precipitation of metallic oxids by alkalies; it dissolves neither heavy nor light hydro-carbons; it is easily miscible with boiler scale preventatives, and boiler cleansing substances, so far as these are not soluble in it, and when mixed with graphite and similar solid lubricants, it forms an emulsion, or a mixture which does not separate. From these properties result the very valuable advantages of glycerin for the purpose in question: it forms a lubricant which is absolutely indifferent against metal, and at the same time does not injuriously affect the interior of the boiler by causing the formation-of scale thereon, but on the other hand tends to prevent the formation of such scale owing to its property of dissolving such scale preventatives as soda, borax, tannin, e c" it offers a very convenient means of introducing these materials into, and mixing them thoroughly with the feed water, while its property of forming stable mixtures with graphite etc. does away with the necessity of special appliances for agitation inthe pining etc.

As suitable proportions may be mentioned:-v

1. Glycerin 92%70 by weight. Graphite 7 2. Glycerin 85% by Graphipe 3% Borax 7--% The mixtures of glycerin with graphite may be prevented from separating in a very easy and practical manner by impregnating the graphite before mixing it with the glycerin, with a suitable quantity of hydro-carbon insoluble in glycerin, such as petroleum, kerosene, toluol, xylol, etc.

- When suitable proportions are used, it is possible by this means to reduce the specific we ght.

gravity of the graphite mixture to thatof the glycerin, andthus cause the particles of graphite to remain in suspension.v

It is best to work up the gra hite with about two-thirds of its weight 0 light petroleum (kerosene) upon mixing this wlth about ten times its weight of glycerin, there results a perfectly stable and smooth emulsion. In this manner, the well-known boiler scale preventing properties of petroleum or kerosene may be utilized.

a What I claim is 1. A lubricant for the cylinders of steam engines, consisting of a large percentage of glycerin with a comparatively small percentage of powdered graphite suspended therein, said lubricant being adapted to be acted upon by the steam in said cylinders,-

which will dissipatethe glycerin and leave nothingbehind except the finely divided graphite, substantially as described.

2. A lubricant for 'the cylinders of steam engines, consisting of alarge percentage of glycerin mixed with a comparatively small percentage of a graphite mixture containing powdered graphite impregnated with a hydrocarbon insoluble in glycerin, said lubricant being adapted. to be acted upon by steam, which will dissipate the glycerin, and leave behind the finely divided graphite, substantially. as described.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses. v

LEONARD CHAPMAN Witnesses CLAUDE WI NoKLEx, JOHN WALKER. 

